IL-2 -330T/G polymorphism and cancer risk: a meta-analysis

Effect of interleukin-2 (IL-2) polymorphisms on multiple myeloma: IL-2RA rs2104286, IL-2 rs2069762 and rs2069763 polymorphisms

Interleukin-2 (IL-2) is a cytokine secreted from T helper type 1 cells and released after induction of T helper cells with major histocompatibility complexes or antigens presented by antigen presenting cells. IL-2 activity and gene polymorphisms have been studied in both solid and hematological malignancies. In the present study, it was aimed to examine the effects of IL-2RA rs2104286, IL-2 rs2069762 and rs2069763 polymorphisms on multiple myeloma (MM) susceptibility, progression-free survival (PFS) and overall survival (OS). A total of 300 patients diagnosed with MM in our clinic between January 2010 and January 2021, and 170 healthy individuals were included. In addition to the demographic data of the patients, MM subtypes, initial stages, prognostic index scores, laboratory results, treatment preferences, and survival data were recorded. The genotypes of the IL-2RA rs2104286, IL-2 rs2069762 and rs2069763 polymorphisms were statistically compared between patients and healthy controls to reveal their effects on MM susceptibility and survival. In the statistical analysis performed to examine the effect of IL-2RA rs2104286, IL-2 rs2069762 and rs2069763 polymorphisms on disease susceptibility, no significant difference was found between the patient and healthy control groups. Patients with the TG genotype of IL-2 rs2069762 had a significantly shorter median PFS and OS compared to others. Patients with the GG genotype of IL-2 rs2069763 had a significantly shorter median PFS compared to others. Having the TG genotype of IL-2 rs2069762 has been shown to be protective for short PFS and OS. Our study results will be guiding in terms of IL-2 based therapies, the future for MM and MM epigenetics.

Helicobacter pylori and non-alcoholic fatty liver disease

Helicobacter pylori is the most prevalent infection worldwide, while non-alcoholic fatty liver disease emerged as the most frequent liver disease. The common occurrence can be either by chance or due to certain pathogenetic factors. Epidemiologic studies revealed that the risk of non-alcoholic liver disease is increased in patients infected with Helicobacter pylori. DNA fragments of Helicobacter pylori were rarely identified in human samples of liver carcinoma and fatty liver. Helicobacter pylori could influence the development of non-alcoholic fatty liver either by hormonal (ghrelin? gastrin? insulin?), or by effect of pro-inflammatory cytokines (interleukin 1 and 8, tumor necrosis factor ɑ, interferon ɣ) and by changes of gut microbiome as well. Probiotic supplementation could improve some clinical parameters of non-alcoholic fatty liver disease and eradication rates of Helicobacter pylori. Regimens used for eradication can be safely administered, although non-alcoholic fatty liver increases the risk of drug-induced liver damage. Controlled studies of the effect of eradication on the development and progression of non-alcoholic fatty liver are warranted.

Helicobacter pylori and cytokine gene variants as predictors of premalignant gastric lesions

Gastric cancer remains the third leading cause of mortality from cancer worldwide and carries a poor prognosis, due largely to late diagnosis. The importance of the interaction between Helicobacter pylori (H. pylori) infection, the main risk factor, and host-related genetic factors has been studied intensively in recent years. The genetic predisposition for non-hereditary gastric cancer is difficult to assess, as neither the real prevalence of premalignant gastric lesions in various populations nor the environmental risk factors for cancer progression are clearly defined. For non-cardiac intestinal-type cancer, identifying the factors that modulate the progression from inflammation toward cancer is crucial in order to develop preventive strategies. The role of cytokines and their gene variants has been questioned in regard to non-self-limiting H. pylori gastritis and its evolution to gastric atrophy and intestinal metaplasia; the literature now includes various and non-conclusive results on this topic. The influence of the majority of cytokine single nucleotide polymorphisms has been investigated for gastric cancer but not for preneoplastic gastric lesions. Among the investigated gene variants onlyIL10T-819C, IL-8-251, IL-18RAP917997, IL-22 rs1179251, IL1-B-511, IL1-B-3954, IL4R-398 and IL1RN were identified as predictors for premalignant gastric lesions risk. One of the most important limiting factors is the inhomogeneity of the studies (e.g., the lack of data on concomitant H. pylori infection, methods used to assess preneoplastic lesions, and source population). Testing the modifying effect of H. pylori infection upon the relationship between cytokine gene variants and premalignant gastric lesions, or even testing the interaction between H. pylori and cytokine gene variants in multivariable models adjusted for potential covariates, could increase generalizability of results.

IFNG +874 A/T is associated with acute lymphoblastic leukemia in Mexican Mestizos

Acute lymphoblastic leukemia (ALL), the most common type of cancer in children worldwide, has one of the highest incidence rates in Mexico. It is a multifactorial disease and different cytokine single nucleotide polymorphisms (SNP), have been associated with ALL expression. Few studies have been published analyzing IFNG +874 T/A and IL2 -330 G/T in this type of leukemia. These SNPs are involved in high or low expression, and are central to cellular immunity, influencing greatly tumor growth. The purpose of this work was to explore the association of IFNG +874 A/T (rs2430561) and IL2 -330 G/T (rs2069762) SNPs with ALL susceptibility and/or protection in 488 Mexican Mestizos patients, as compared to 950 Mexican Mestizo healthy controls. The results demonstrated that IFNG +874 T allele (pc = 0.00004, OR = 0.673) and the TT genotype (pc = 0.00015, OR = 0.349), protect against ALL expression with no specific gender association; however, the TT homozygote genotype (vs. TA+AA) seems more protective in males (pc = 0.00683). IL2 -330 G/T does not contribute to the development of ALL. In healthy Mexicans, the most common genotypes for IL2 and IFNG, are the low cytokine producers, suggesting that the genetic background in this ethnic group, may be partly responsible for the high incidence of ALL. These results show for the first time in Mexicans, the relevant role that IFNG SNP has in the genetic etiology of ALL. Thus, a large group of patients belonging to different ethnicities will be very helpful to study in order to demonstrate if these SNPs contribute to the genetic etiology of ALL, as shown here in Mexican Mestizos.

Polymorphisms and haplotypes of the interleukin 2 gene are associated with an increased risk of gastric cancer. The possible involvement of Helicobacter pylori

Interleukin 2 (IL-2) is a pro-inflammatory cytokine that is mainly synthesized by immunoregulatory T helper cells and which plays an important role in antitumor immunity. Helicobacter pylori (H. pylori) is a gram-negative bacterium that colonizes the gastric mucosa and induces the production of IL-2. This process increases the magnitude of inflammation and may influence the development of gastric pathologies. In light of the possible involvement of IL-2 and the presence of H. pylori in gastric diseases, this study investigated possible associations between the IL-2 polymorphisms +114 T>G (rs2069763) and -330 T>G (rs2069762) and the development of gastric cancer; these associations were then correlated with the presence of H. pylori. Gastric biopsies were obtained from 294 dyspeptic patients (173♀/123♂). Of these samples, 181 were chronic gastritis samples (102♀/79), 62 were samples of intact gastric mucosa (47♀/15♂), and 51 were samples of gastric cancer (22♀/29♂). PCR-RFLP was used to characterize the +114 T>G and -330 T>G polymorphisms. Considering the genetic characteristics of the study population and based on the codominant model, a high risk of gastric cancer among patients with normal gastric tissue and patients with gastric cancer was found in subjects with the IL-2-330 GG genotype (OR=6.43, 95% CI: 1.47-28.10, p=0.044). The data was adjusted for the presence of H. pylori. Among patients with gastritis and patients with gastric cancer, a high risk was found among subjects with the IL-2-330 GG genotype (OR=4.47, 95% CI: 1.84-10.84, p=0.0022). When the IL-2 +114 polymorphism was analyzed, similar results were found. Among the patients with normal gastric tissue and the patients with gastric cancer, subjects carrying the +114 TT genotype were found to be at a high risk of gastric cancer (OR=5.97, 95% CI: 1.60-22.27, p=0.013). This data was also adjusted for the presence of H. pylori. Among patients with gastritis and patients with gastric cancer, a high risk was found in subjects carrying the +114 TT genotype (OR=6.36, 95% CI: 2.66-15.21, p<0.0001). The haplotype was also analyzed. The -330G/+114T haplotype was found to be significantly associated with gastric cancer. Therefore, our results show that, among patients with H. pylori infection, the -330 GG and +114 TT genotypes are significantly associated with a high risk of developing gastric cancer, as is the -330G/+114T haplotype.

Association between two interleukin-2 gene polymorphisms and cancer susceptibility: a meta-analysis

Background

Several epidemiological studies have illustrated that polymorphisms in interleukin-2 (IL-2) were associated with diverse cancer types. However, recently published statistics were inconsistent and inconclusive. Therefore, the current meta-analysis was performed to elaborate the effects of IL-2 polymorphisms (rs2069762 and rs2069763) on cancer susceptibility.

Material and methods

A total of 5,601 cancer cases and 7,809 controls from 21 published case–control studies were enrolled in our meta-analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association between IL-2 polymorphisms and cancer susceptibility.

Results

Our study demonstrated an increased susceptibility to cancer in rs2069762 (G vs T: OR =1.268, 95% CI =1.113–1.445; GG vs TT: OR =1.801, 95% CI =1.289–2.516; GT vs TT: OR =1.250, 95% CI =1.061–1.473; GG + GT vs TT: OR =1.329, 95% CI =1.118–1.579; GG vs GT + TT: OR =1.536, 95% CI =1.162–2.030). In the subgroup analysis, increased susceptibility to cancer was identified in the hospital-based group and P_HWE<0.05 (P-value of the Hardy–Weinberg equilibrium [HWE]) group. In addition, a positive association with cancer susceptibility was observed among both Chinese and non-Chinese. However, no relationship was detected between the rs2069763 polymorphism of IL-2 and cancer susceptibility.

Conclusion

To conclude, rs2069762 polymorphism of IL-2 contributed to an increased susceptibility to cancer, whereas no association was identified between rs2069763 polymorphism and cancer susceptibility. Further detailed studies are warranted to confirm our findings.